I don't have a CJ but same basic principle applies to all of them. Mount two on the front bumper and mount two on the back frame rails, one of the left one on the right. Drilling holes and mounting them take about 2 hours give or take to do the front and the back. My rational behind having two in the back is what happens if the side you have your hook on is buried in mud, or there is a rock blocking it? Go for both sides, Harbor Frieght sells 10,000lbs forged steel hooks for 10 bucks. Also I would suggest replacing the factory bolts with Grade 8's for some added strength.
4 hooks, 8 bolts and assorted hardware cost me about $55-65 dollars. Best recovery upgrade I ever did.